A digital library is an important part of the "information highway". In general, a digital library includes several components such as a network, a database server, mass storage, and user interfaces. Usually, an archive material is entered into a digital library by the following steps:
1. digitizing the archive material by manual entering, photoelectric recognition, electronic scanning, digital sound and image recording, etc.; PA1 2. storing the digitized archive material into a mass storage pool of the digital library; and PA1 3. extracting record items associated with the archive material and physical or logical addresses of the digitized archive material on the mass storage media of the digital library, and loading the record items and physical or logical addresses into databases of the digital library. PA1 1. The formats in which the archives are recorded on CD-ROMs are inconsistent with each other; PA1 2. On CD-ROMs there is no index information for each archive; and PA1 3. CD-ROM archives have to be loaded into database management systems of electronic digital libraries manually. PA1 means for reading record information stored on the removable mass storage media; and PA1 means for loading said record information into the database tables of the digital library.
Once an archive has been entered into a digital library, readers or users will be able to obtain required materials by accessing the digital library via the computer terminals connected to the network.
Nowadays, in the "information highway" environment, information is exchanged mainly by means of removable mass storage media used as physical carriers, apart from direct transmission using networks. At the present time, CD-ROM is one of the most important media. In a digital library, text, photographs, movies, music and other archive materials are usually digitized and stored on CD-ROMs, forming CD-ROM archives. However, CD-ROM archives have the following problems:
As a result, a large quantity of manpower, material resources and time will be wasted while CD-ROM archives are loaded into databases of digital libraries. Also, CD-ROM archives prepared for one particular digital library can be used only in that system. If CD-ROM archives prepared specially for one digital library are to be used in another digital library, these CD-ROM archives have to be loaded into databases manually. Thus, the distribution and exchange of CD-ROM archives are greatly hindered.